A Structure Lying External to One or More Cells Which Provides Structural Support For Cells or Tissues; May Be Completely External to the Cell (as in Animals and Bacteria) or Be Part of the Cell (as in Plants).

Catalysis of the Hydrolysis of Internal Alpha Peptide Bonds in a Polypeptide Chain by a Mechanism in Which Water Acts As a Nucleophile One or Two Metal Ions Hold the Water Molecule in Place and Charged Amino Acid Side Chains Are Ligands For the Metal Ions.

Catalysis of the Hydrolysis of Peptide Bonds by a Mechanism in Which Water Acts As a Nucleophile One or Two Metal Ions Hold the Water Molecule in Place and Charged Amino Acid Side Chains Are Ligands For the Metal Ions.